One method of performing a surface operation on an object (e.g., painting) is to place the object on a support platform so that the surface portion is exposed, performing the surface operation, and then moving the object to a different position on the platform to expose another surface portion and then repeating the surface operation. This can be a time consuming operation particularly where a large number of parts are involved. Accordingly, it would be desirable to automate such a system as much as possible, and in particular to automate the operation of moving and positioning of the object(s) so as to properly expose the various surface portions of the object(s) or workpiece(s).
Another consideration in a manner so that the particular workpieces can be identified before and after the surface operation. For example, in an industry such as the aircraft industry, for purposes of quality control it is desirable in some instances to identify the origin of the particular part throughout its manufacture, painting, etc. If identification is applied directly to the part itself, this may impair the ability to paint the exposed surface areas completely. This problem can be alleviated by maintaining identification of the particular tray or support platform on which the part is carried through the automated system, but this would of course necessitate that the workpiece remain associated with the same tray.
Another consideration is that the system should be arranged so that it does not demand constant attention of an operator or overseer. For example, if human input or activity is required in the system, it would be desirable that such input would not require constant attendance or activity of the person throughout the operation.
A search of the patent literature in connection with U.S. Pat. application Ser. No. 761,980, entitled "Apparatus and Methods for Engaging a Workpiece", filed Aug. 2, 1985 by Fuller et al now U.S. Pat. No. 4,773,816, disclosed a number of U.S. patents, and other U.S. patents were developed during the prosecution of that application. These are listed below, in addition to other patents which have come to the attention of the applicant.
In U.S. Pat. No. 4,121,817 (Pavlovsky) there is disclosed an apparatus for engaging an irregularly shaped workpiece including a lower support plate having holes therein arranged to receive vertical support members of various heights to support a workpiece for retention thereof in a fixed relationship with a support plate by an upper opposing clamp.
In U.S. Pat. No. 3,463,478 (Hennessey) there is disclosed an apparatus for supporting a workpiece in a selected position including a base having openings for receiving pins therein which support the workpiece at a desired orientation relative to the base.
In U.S. Pat. No. 4,098,046 (Papa) there is disclosed a guide frame for the retention of slideable articles wherein the guide frame includes a top and bottom members each having opposing cantilevered ribs terminating in opposing parallel spaced apart bars which form top and bottom channels for receiving and engaging the article therein.
In U.S. Pat. No. 2,621,807 (Rendich) there is disclosed an apparatus for position and retaining display devices including a base member having spaced apart openings therein for receiving support members at predetermined locations to engage and accurately position a display device on the base.
In U.S. Pat. No. 3,559,980 (Terai et al) there is disclosed a system for adjusting the position of a plurality of jigs for supporting several workpieces in proximate relationship prior to welding the workpieces together wherein the controller moves the jigs vertically to form a support conforming to the shape of the workpiece for receiving the workpiece thereon.
In U.S. Pat. No. 3,175,820 (Schlier) there is disclosed a rotary table for rotatably supporting workpieces thereon wherein threaded support elements are vertically adjusted relative to the table to receive and support the workpiece thereon.
In U.S. Pat. No. 3,178,168 (Abernathy) there is disclosed an apparatus for positioning and supporting a container including a base having receptacles therein for receiving and supporting upright dowels to receive an inverted box thereon in order to perform operations on the box.
In U.S. Pat. No. 3,181,858 (Daniels) there is disclosed a support for a workpiece including a plurality of yielding members which are resiliently biased to a vertical position, but which yield to a portion of the workpiece extending below the plane thereof when the workpiece slides across the top of the support, and then which return to an erect position.
In U.S. Pat. No. 3,442,251 (Perkel) there is disclosed an apparatus for coating articles including a container having a rotary shaft supporting opposing adjustable arm members forming a grid structure for engaging the articles therebetween, and a sprayer assembly for applying a solution to the article as it is rotated in the container.
U.S. Pat. No. 2,370,698 (Vaughn) shows a device for quickly turning over small objects, with these objects being supported on wire mesh screens. This screen, with the objects being positioned thereon, is placed on a sponge rubber surface that is in turn mounted to a pivotally mounted plate. There is a second plate, pivotally mounted to the first plate and also having a wire mesh screen backed by sponge rubber. The second plate is pivoted upwardly and downwardly so that the second screen engages the objects on the first screen. Then the two plates together, holding the objects secured between the two screens and the sponge rubber members, are rotated 180% so that the objects come to rest on the second screen.
U.S. Pat. No. 4,295,776 (Payne et al) discloses a device for transferring bulk goods between pallets. A first pallet having the bulk goods thereon is placed on a floor of the inverting member and a lid is moved to clamp a second pallet on the opposite side of the load. The inverter is then rotated to cause the load to rest on the second pallet.
U.S. Pat. No. 1,711,250 (Purinton) shows a process and apparatus by which two sides of objects, such as buttons, can be painted. The buttons are loaded from a hopper onto an assembling tray 13 which has recesses shaped to receive the buttons with the concave middle face facing downwardly, but to reject the buttons which are inverted. Then a screen is placed on the buttons on the assembly tray, with the assembly then being inverted so that the buttons come to rest on the screen with their concave side facing upwardly. Then the concave facing surface of the buttons can be painted, such as by spray painting. The buttons are then moved off the tray to a collecting location. To paint the other side of the buttons, the buttons (with their concave sides painted) are again placed on an assembling tray, with the assembling tray being vibrated to cause the buttons to fall into the proper recesses. Then a second inverting tray, having recesses complementary to the assembly tray, is placed on top of the buttons. The two trays are then inverted, so that the buttons now lay on the reversing tray with the painted concave surfaces facing upwardly. A screen is then placed on the reversing tray, and both of these are inverted so that the buttons come to rest on the screen with the unpainted convex surfaces facing upwardly. These convex surfaces can then be painted.
U.S. Pat. No. 3,395,439 (Palesi et al) shows an apparatus for mounting electrical components having lead wires. A cover with a resilient pad is brought into engagement with the electrical components with the pad clamping the components against the board. The apparatus with the components clamped to the circuit board may then be inverted for joining the lead wires to the conductive circuit of the circuit board.
U.S. Pat. No. 3,902,512 (Armstrong et al) shows a washer using a vibrating feed element having bristles, with the vibrating movement causing the articles to be washed to be moved through the washer.
U.S. Pat. No. 4,572,850 (Bailey) shows an apparatus for supporting objects of various shapes for submergence in a liquid. There is a pair of sheets of elastomeric material which engage the object to hold it in place.
U.S. Pat. No. 4,483,269 (Down) shows a fixture for holding flexible printed circuit board substrates by means of screens of a wire mesh material.
U.S. Pat. No. 4,108,105 (Wiggins) shows a part gauging control system for a liquid spray apparatus. There is a laterally movable plate 17 which is moved into engagement with a workpiece which is about to enter the painting chamber. The position of the plate 17 as it engages the workpiece is relayed to circuitry which in turn determines the position of the spray head means in the painting chamber. Also, the exit doors are opened in accordance with the dimensions of the workpiece.
U.S. Pat. No. 4,042,734 (Wiggins) discloses a method and apparatus for spray coating where there is a plurality of atomizing nozzles. The article to be painted is conveyed past the spray station and the spray head or heads are moved along a particular path to accomplish proper painting.
U.S. Pat. No. 4,129,092 (Wiggins) discloses substantially the same subject matter as U.S. Pat. No. 4,042,734.
U.S. Pat. No. 4,220,430 (Meleer et al) shows a device for positioning a movable part of a machine tool, such as positioning a spindle relative to a housing. There is a transmitter connected to one part and a differential transmitter secured to the other part. First and second heads are positioned relative to first and second transmitter surfaces so that the heads produce a control signal in accordance with the amount of the head aligned with the surfaces. Control means are connected to the respective heads for moving the machine part to the appropriate location.